LAS CRUCES >> A coalition of border sheriffs is opposing a plan to designate scenic mountainous areas in Doña Ana County as a federal monument.

The Albuquerque Journal reports (http://bit.ly/1m16Opk) that in a letter to New Mexico's two Democratic senators, Doña Ana County Sheriff Todd Garrison says the group believes plan will leave the land vulnerable to illegal activity.

U.S. Senators Martin Heinrich and Tom Udall have introduced legislation that calls for designating about 780 square miles near Las Cruces as the Organ Mountains-Desert Peaks National Monument.

The lawmakers say the proposal takes pains to improve law enforcement's ability to secure the border region and allows rancher to keep grazing livestock.

Garrison says deputies would have a harder time accessing the monument area, leading to a rise in cross-border crime.